1. Field of the Invention
This invention relates to methods and apparatus for forming elongated products and, more particularly, to methods and apparatus for deforming an elongated workpiece so as to form an integral article, which integral article includes a number of parallel-extending elongated members.
2. Description of the Prior Art
In the art of forming elongated products, it is known to utilize hydrostatic extrusion techniques, wherein hydrostatic pressure is applied to a billet within a chamber such that the material of the billet is rendered more ductile as the billet is forced through an aperture in a die located at one end of the chamber. Some examples of such techniques may be found in my U.S. Pat. No.3,740,985, application for the reissue of which has been made on Jan. 4, 1974 under Ser. No. 430,984, and in my copending application, Ser. No. 612,875, filed September 12, 1975 and entitled, "Continuous Wire Extrusion".
In my copending application Ser. No. 638,494, filed Dec. 8, 1975 (now abandoned) and entitled, "Methods and Apparatus for Forming and Handling Elongated Products," there are disclosed techniques for forming and handling elongated, integral structures, such as tapes, wherein the tapes take the form of a number of elongated products, such as wires, extending longitudinally in parallel and joined together along their lateral edges by additional elements of interconnecting material. Such techniques involve the deforming of a workpiece, e.g., by hydrostatic extrusion of the workpiece through a die with a suitably configured aperture, in order to form the tapes, which tapes may include parallel-extending elongated products of various shapes. Two specifically suggested shapes for the cross-sections of the elongated products are generally semicircular and generally square. Examples of such a tape which includes a number of generally semicircular, parallel-extending, elongated products, and of one of the products, are illustrated in FIGS. 1 and 2 of the drawing.
It is considered desirable to be able to product tapes which include fully circular, parallel-extending, elongated products, as shown in FIG. 3 of the drawing. It should be clear, however, that, in order to form such tapes by the technique disclosed in my copending application Ser. No. 638,494, as discussed, the appropriate die configuration would have to include a number of relatively very sharp and very thin projecting edges in order to define the spaces between adjacent circular portions of substantially tangent elongated products. It is, of course, not considered feasible to utilize a die with projecting edges of such a nature, in view of the likelihood of edge breakage and/or extremely rapid edge wear due to the high pressure associated with tape formation. Accordingly, it should be evident that there is a need for the provision of other methods and apparatus for forming tapes composed of parallel-extending, elongated products, each having a substantially fully circular cross-section.